It's the follicular phase. For me, it can be 1 day or 1 week of feeling absolutely awful.
Dreadful fatigue, nausea, tight tummy, so bloated, constipation, brain fog.
I'm mid forties, it started a few years ago. Not every month but increasingly more months than not.
Although I'm peri menopausal I've seen a few comments that it does affect younger people as well. Onset after having children seemingly.
Anyone else?
What I'm really trying to find out is whether it's caused by;
A) a rush of hormones, namely estrogen, perhaps worsened by cycle being annovulatory
B) an inability of estrogen to take flight and therefore a lack of it
C) Low progesterone
D) Something else
I've only recently read of POST menstrual syndrome, which fits with this.